In general, the present invention relates to an information-processing apparatus, an information-processing method, a network system, and a program. More specifically, the present invention relates to an information-processing apparatus, an information-processing method, a network system, and a program, which can exchange streaming data without regard to the type of the compression and decompression technique of the streaming data by addition of a program to be executed for carrying out processing on the streaming data to the streaming data and transmission of the program along with the streaming data.
There are many servers for distributing streaming data such as audio data and moving-picture data, which can be displayed in a real-time manner while the data is being received through the Internet. Picture or audio information is input through a video camera and a microphone and converted into data by a video-capture card and/or a sound card before being compressed by using an encoder. The compressed data is kept by a distribution server as a file of streaming data to be transmitted to a client as requested by the client on an on-demand basis. In addition to such an on-demand system, there is also provided a system in which compressed data is distributed to a plurality of clients at the same time.
In either system, while receiving distributed streaming data, a client uses a decoder conforming to the technique of compressing the received streaming data to decompress the data before outputting the data to a display unit and/or a speaker.
However, there are a number of data compression and decompression techniques such as an MPEG (Moving Picture (coding) Expert Group) 2 or 4, MP3 (MPEG Audio Layer-3) and ATRAC (Adaptive Transform Acoustic Coding™). For this reason, the system described above has a problem that the client must have many decoders if the client receives various kinds of streaming data compressed by using a variety of compression techniques.
In addition, there is also raised a problem that the distribution server must adopt several different compression techniques for different kinds of streaming data in order to keep up with demands raised by a number of clients.
Moreover, a client can be a portable terminal such as a PDA (Personal Digital Assistant). In this case, since a space for a storage device and the storage capacity thereof are small in the portable terminal, it is difficult for the client to have a plurality of decoders. Thus, there is raised a problem that the portable terminal can be used only for handling streaming data compressed by adoption of a certain compression and decompression technique.